SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f8cf43413f1e3e897ea11d8447b5605033fc5bbf61eeaa72234854602d334dd' 
  AND token = 'nzS1pUyzghuC7xCqOUV9pugJpZq+LkACTJL+GSAIggQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}